Adolescents who have received care in Emergency Departments represent a group who do not regularly seek health care from facilities providing preventative reproductive health screening yet who have a high prevalence of asymptomatic and a unrecognized STDS. In this project urine LCR screening for Neisseria gonorrhoeae and Chlamydia trachomatis provided through outreach (as opposed to clinic-based) activity and guided by a social network informed screening protocols originating with infected individuals identified at the time of emergency room attendance will be studied. The specific aims of this project are: 1) To define the prevalence of undetected N. gonorrhoeae and C. trachomatis in adolescents receiving care for reasons other than possible STD-related complaints at a large urban emergency room; 2) To characterize in an exploratory fashion, the health seeking behaviors, social (and sexual) networks, and other epidemiologic and behavioral characteristics of adolescents with and at risk for STDs attending the emergency room; 3) To conduct a randomized clinical trial comparing traditional health department partner notification activities to a social network-informed screening intervention for identifying and testing bacterial STDs using LCR tests; 4) To d4evelop, in partnership with our local health department, new strategies for identifying and treating STDs in a high prevalence community as well as opportunities for preventing future infection in adolescents identified through opportunistic screening performed at the time of emergency room attendance. Outcome measures will include descriptive analyses of reproductive health care seeking behaviors in adolescents seen in the emergency room, the prevalence of otherwise undetected bacterial STDs in adolescents seen in emergency room, and the numbers of infected persons identified through netowrk- informed outreach and screening per unit of Health Department Disease Int4rvention Activity time. The project has the potential to provide one of the most randomized clinical trials for evaluating traditional partner notification activities as compared to other outreach mechanisms for identifying individuals with and at risk for STDs, as well as providing a new strategy for STD intervention in adolescents, the group with highest STD morbidity.